Nozzle for dry powder extinguishers



March 18, 1952 F. B. ALLEN NOZZLE FOR DRY POWDER EXTINGUISHERS Filed NOV. 14, 1950 2 SHEETS -SHEET 1 INVENTOR. FRA N/rB. AL LEN BY CZAM/ Him ATTORNE)? March 18, 1952 F. B. ALLEN 2,589,213

NOZZLE FOR DRY POWDER EXTINGUISHERS Filed NOV. 14, 1950 2 SHEETS-SHEET 2 INVENTOR. F/eA/v/(fiALLE/v avuw w 14 7' TO P/VEX Patented Mar. 18, 1952 NOZZLE FOR DRY POWDER EXTINGUISHERS Frank B. Allen, Towaco, N. J., assignor to -0- Two Fire Equipment Company, Newark, N. J., a corporation of Delaware Application November 14, 1950, Serial No. 195,571

This invention relates to fire extinguishing apparatus and particularly to a nozzle suitable to control the flow of a dry powder extinguishing agent.

It is important in a nozzle of this type that it be so designed as to allow the free flow of the extinguishing powder. Further, the nozzle should be so arranged as to be self-cleaning during the discharge. In addition, the dry powder extinguishing agent should be expelled with sufficient force or velocity to reach a fire in an inaccessible location while the operator remains a safe distance from the fire. In obtaining sufficient projection distance of the fiuid, it is im-.

portant that the velocity of the stream of issuing agent be such that a negligible amount of air will be entrained. An excess of air is disadvantageous in that it accelerates the combustion of the fire and nullifies the action of the extinguish-T lIlg agent.

A prior construction has been made in which the. issuing stream of dry powder and its expelling agent has been impinged against the inner surface of an outlet chamber and then redirected outwardly in a stream. In order to provide for the discharge from an orifice against the inner wall of the outlet chamber, a cone-shaped member with orifices in its walls has been used, the member having the same internal diameter as that of the supply piping and positioned at the end partively large size of the horn, such constructions are unwieldy and present diffioulty in the transportation of the extinguisher as well as in its use in inaccessible locations.

The invention aims to overcome the difiiculties and disadvantages of prior constructions in providing a nozzle for a dry powder fire extinguisher which is self-cleaning.

Another object of the invention is to provide a dry powder nozzle with a good projection characteristic without the entrainment of an appreciable amount of air.

Another object of the invention is to provide 4 Claims. (01. 169-1) a dry powder nozzle'which is simple and economical in manufacture, eflicient in operation and durable in use.

In accordance with the invention, the foregoing objects are accomplished by providing a dry powder nozzle having a discharge outlet causing a turbulence therein of an issuing stream to reduce its velocity and for increasing its cross-sectional area. Preferably, a construction is utilized in which a barrier is placed in an enlarged portion of the outlet so that the velocity of the issuing stream is reduced by turbulence while its crosssectional area is increased.

A construction in accordanc with the invention is advantageous i that a nozzle of ample capacity may be made of comparatively small size for ease in storage and use.

Other objects and advantages of the invention will be apparent from the following description and from the accompanying drawings which show, by way of example, an embodiment of the invention.

In the drawings:

Figure l is a perspective view of a dry powder fire extinguisher equipped with a nozzle constructed in accordance with the invention.

Figure 2 is an enlarged side view of the nozzle in accordance with the invention in an assembly with a shut-off Valve.

Figure 3 is a vertical sectional view of the nozzle shown in Figure 2.

Figure 4 is a top view of the nozzle shown in Figure 2.

Figure 5 is an end view of the nozzle shown in Figure 2.

Referring to the drawings there is shown a fire extinguisher I having a hose line 2 terminating in'anozzle 3 in accordance with the invention. The extinguisher container may be of the usual type retaining therein a charge of dry powder together with a charge of compressed gas which may be released to expel the powder by inverting the extinguisher and striking the top thereof against a surface, such as the ground. The powder is expelled by the gas charge through the hose 2 and may be intermittently discharged from the nozzle 3 as desired. The ozzle 3 comprises a casing 4 having a horizontally extending inlet passage 5, an inclined valve chamber 6 and a discharge outlet passage 1 inlarged at its outer end to receive a baflle member 8. The cylindrical valve member 9 is reciprocable in the valve chamber 6 to close the outlet passage 1 and is actuated by means of a squeeze grip type operating handle in pivotally carried by the housing and normally urged into the closed position by resilient means, such as the spring I I.

The nozzle casing 4 may be made of any suitab1e material, such as metal or plastic and has an enlarged portion I2 at the end of its inlet passage formed with a threaded inner surface I4 for connection to the hose 2. The other end of the inlet passage 5 is turned upwardly as indicated at I5 to intersect the valve chamber 6 which is formed with its lower end sloping toward the discharge passage I so as to cooperate with the inlet passage 5 to provide a free flow passage for the powder. It is preferred that the valve chamber have a somewhat enlarged portion as indicated at I6 so as to facilitate the flow of the powder about the valve member 9 when the valve is in the opened position. The valve member 9 is cylindrical in shape and has its lower end II beveled as indicated at I9 to guide its entrance into the lower portion of the chamber 6 defined by wall 20 as the valve is opened and closed. Upper end 2I of the valve member 9 is made of a diameter such that it closely fits the wall of the chamber 5 with small clearance, so that a seal is formed by the packing of small particles of powder in the clearance space between the valve member and the wall. The outer end of the valve member 9 is formed with an annular reduced portion 22 for engagement with U-shaped end 24 of the grip handle III.

The casing 4 is apertured as indicated at 25 and fitted with a pin 26 for the pivotal mounting of the grip handle I9. The casing also has an upwardly and forwardly extending projection 21 adapted to maintain in position the lower end of the spring II.

The grip handle I!) is generally of channel cross-sectional and has its valve engaging end turned downwardly and inwardly, it being slotted as indicated at 29 to receive the reduced portion 22 of the Valve operating member 9. The lower surface of the grip handle I0 has a downwardly and rearwardly extending portion 39 oppositely positioned to the projection 21 of the casing 4 so as to provide means for the engagement of the ends of the spring I I therebetween. The outer end 3| of the grip handle I II is given a hand conforming shape so that the nozzle may be readily carried by engaging the fingers about the valve casing 4, the valve being operated by squeezing the grip handle I0 with the palm of the same hand.

The construction of the nozzle thus far described has been shown and claimed in a copending application of Frank B. Allen and Norman H. Siebens, Serial No. 74,355, filed February 3, 1949 and titled Nozzle for Powder Fire Extinguisher.

In accordance with the invention, the outer end of the outlet passage I is enlarged to provide an expansion chamber 32 having a diameter somewhat greater than the diameter of the passage I, so that the area of the enlarged portion or expansion chamber 32 is slightly greater than twice the area of the outlet passage I, the length of the expansion chamber being about one-third its diameter. In order to provide turbulence in the issuing fluid of dry powder and its expelling fluid, a baffle member 34 is placed in the enlarged portion 32 of the discharge outlet. In order to facilitate the support of the baflie member in position, it is preferably made in cup-shape form with a depending skirt 35 having a threaded exterior surface adapted to engage with a corresponding threaded surface on the inner wall of the enlarged portion 32. The face of the baflle member 34 is preferably formed with openings 36 therein leaving a generally Y-shaped closed portion 31 providing an obstruction in the flow of the gas outwardly from the outlet passage I.

In a preferred construction, the closed portion 31 of the bafile member 34 would occupy approximately half the area of the expansion chamber. However, the preferred dimensions of both the baiile member and of the expansion chamber may vary somewhat depending upon the rate of flow desired, the range of the discharge, and the spread of the pattern of the discharge.

The nozzle is operated by depressing the grip handle I 0 to raise the valve member 9 in the valve chamber 6 and permit the flow of the dry powder and its expelling gas past the lower end [I of the valve member. The mixture of gas and powder strikes the Y-shaped member 31 causing turbulence and a decrease in velocity of the issuing mixture with an increased cross sectional area of discharge. As pressure is released on the grip handle I9, the spring II urges the outer end of the handle upwardly causing the valve member 9 to be returned to the closed position cutting off the flow of the gas and powder. By reason of the construction, no pockets or recesses are formed wherein the powder may pack. Any residual loose powder remaining within the valve structure or within the outlet passage I or clinging to the Y-shaped closed portion or baffle member 31 is blown away at the start of the next discharge period.

While the invention has been described and illustrated with reference to specific embodiments thereof, it will be understood that other embodiments may be resorted to without departing from the invention. For example, while the baffle member 31 has been shown of generally Y-shape, other constructions might be utilized providing for an expansion and turbulence of the gas in the expansion chamber 32 of the outlet passage. Therefore, the form of the invention set out above should be considered as illustrative and not as limiting the scope of the following claims.

I claim:

1. A nozzle for a dry powder fire extinguisher comprising a housing having an outlet, the outer end of the outlet of enlarged cross section to provide an expansion chamber, and a bafile member positioned at the outer end of the enlarged portion of the outlet to provide an outer wall for the expansion chamber, the end of the baflie member of generally Y shape and supported by the wall of the outlet.

2. A nozzle for a dry powder fire extinguisher comprising a housing having an outlet. the outer end of the outlet of enlarged cross section to provide an expansion chamber, and a baffle member positioned at the outer end of the enlarged portion of the outlet to provide an outer wall for the expansion chamber, the baffle member having a center portion and legs extending outwardly therefrom to support the baffle member.

3. A nozzle for a dry powder fire extinguisher comprising a housing having an outlet passage, the outer end of the outlet enlarged to provide an expansion chamber having an end wall approximately double the area of the outlet passage and a length approximately equal to the radius of the passage, and a baiiie member adjacent the outer enlarged end of the outlet to provide an outer wall for the expansion chamber. the baffle member occupying approximately half of the enlarged outlet passage area.

4. A nozzle for a dry powder extinguisher comprising a housing having an outlet passage enlarged at its outer end to provide an expansion chamber, a bafile member positioned in the enlarged portion of the outlet at its outer end, the baffle member having a cylindrical wall section to fit the outlet of the housing, and a Y-shaped flat baiile positioned on the outer end of the cylindrical wall section and attached thereto, whereby the stream issuing from the outlet passage is reduced in velocity and increased in cross-sectional area to minimize the entrainment of air.

FRANK B. ALLEN.

v Number Name Date 2,484,943 Guise et al Oct. 18, 1949 

